Quote:
Originally Posted by skyking
Hard to believe, right?
Somebody posted info from a test using a brick shape. Fairing in the back was the single biggest improvement, and here is my take on why:
No matter how you smooth the flow going onto your rig, it still displaces X amount in cross section. Still 13 high and 8 wide. No way to fool that.
At the back you can "let" that air off very gently and efficiently, or let it slam shut.
If you let it slam shut the turbulence and vacuum is so great, a car can ride with almost no power input in the wake of your motorhome. IF you think about it, you could pull a smaller motorhome along behind you  |
Thanks Sky! Now I think I'm
finally starting to understand this aero stuff based on your explanation.
I was also one of the people who couldn't understand how the shape of the back of the vehicle was more important than the front. It just seemed counter-intuitive. Who the heck cared what happened to the air after the car was already through it, right? The most important part had to be the front of the car since that was cutting into the air first.
Over the last couple of months here, I've been reading about laminar flow, attached air, generated vortexes, etc. It seemed that everybody else was able to follow the conversation and I was...LOST.
Your explanation about
"letting the air off very gently and efficiently or letting it slam shut" painted a picture of it that finally made it click in my thick head.
I kinda feel stupid that it took me this long to understand it.
And to think that I had ignored this thread until tonight because I thought that there wouldn't be anything discussed in a conversation of motor homes that would pertain to my little Camry...
Thanks!
John